The present invention relates to medical instruments. More particularly, the present invention relates to an articulated mechanism useful in devices such as forceps, single or multiple sample biopsy devices, articulated electrodes and the like.
Devices for the retrieval of tissue samples from within a patient are frequently used in conjunction with instruments such as flexible endoscopes. Endoscopes allow the visualization of internal structures of a patient by a clinician without the need for conventional exploratory surgery. When suspicious lesions or tissue masses are encountered during an endoscopic examination, it is helpful to excise and remove a small sample of the tissue for further analysis by a pathology laboratory.
Flexible biopsy forceps are often used to perform such tissue excision and retrieval. Conventional biopsy forceps may consist of an elongated, tightly-wound spring-coil body. The spring body has a control assembly at a proximal end and a jaw assembly at a distal end. The control assembly is typically a hand-operated push-pull mechanism that slides a control wire back and forth through a lumen of the spring-coil body. The control wire is usually attached to a pair of pivoting jaws in the jaw assembly. Pushing and pulling on the control wire opens and closes the jaws, respectively. Moreover, the jaws are typically joined to the body through a pivot pin which spans at least a portion of the lumen. Thus, the lumen is typically at least partially blocked or occluded by mechanical elements.
When used with a flexible endoscope, the forceps are inserted into the working channel of the endoscope and advanced distally. The tip of the endoscope is directed by the clinician using controls on the proximal end of the endoscope. Once the target site has been identified and is under direct vision, the forceps are advanced distally out of the working channel and the jaws are opened. Upon contact with the tissue, the jaws are tightly closed and the forceps are retracted slightly to cut and remove the tissue sample. Flexible biopsy forceps can also be used without an endoscope, as in, for instance, cardiac muscle biopsy procedures. In such procedures, the flexible biopsy forceps device is inserted through a blood vessel into a heart chamber, where a sample of cardiac tissue is excised.
With certain types of endoscopic examinations, it is necessary to take more than one tissue sample. For example, in surveying a region of a bowel for specific disease states, it is sometimes necessary to take between ten and twenty tissue samples. In these instances, the use of conventional biopsy forceps is time-consuming because the forceps must be withdrawn and re-inserted after each sample has been excised. Maintaining the tip of the endoscope in a steady position during the removal and re-insertion of the forceps is often a tedious and difficult task. Accordingly, the clinician's ability to keep track of which areas have been biopsied and which have not can be impaired. The impairment of this ability can result in a frustrating and lengthy procedure for both the patient and clinician.
There is, therefore, a need for a biopsy device capable of retrieving more than one tissue sample from within a patient. It is also preferable for the collected samples to be of a size comparable to those obtained from conventional biopsy forceps devices, and for such samples to be easily removed from the device. Moreover, it is desirable for the samples to be held in the order of collection for identification of the source of each sample. It is further desirable for such a device to be relatively inexpensive and easy to use. In addition, a variety of other instruments such as graspers, spreaders, electrodes, single sample biopsy devices and the like would benefit from a single low profile articulating mechanism such as that disclosed herein.